MA 109 MATH FOR LIFE SCIENCE WEEK 1

MA 109 MATH FOR LIFE SCIENCE WEEK 1 : ARITHMETIC REVIEW PEMDAS & FRACTIONS UNITS 5 - 10

UNIT 5 - PEMDAS It is important to perform operations in a standard order in order to obtain consistent results. 1. 2. 3. 4. Perform any operations within Parentheses (starting with the innermost set(s) of parentheses first). Simplify any Exponents Multiply and Divide from left to right as they occur. Add and Subtract from left to right as they occur. Remember “PEMDAS”: Please Excuse My Dear Aunt Sally” 2

EXPONENT REVIEW 3

UNIT 5 - PEMDAS Example – Solve 6÷ 2× 4 –(7 – 2) Example – Solve 785 – 39 + (14÷ 2)2 4

UNIT 5 - PEMDAS Example – A phlebotomist does venipunctures to obtain blood samples from patients. One morning he fills 6 vacuum tubes with 12 milliliters (m. L) of blood, 3 vacuum tubes with 8 m. L of blood, 12 vacuum tubes with 15 m. L of blood, and 5 vacuum tubes with 10 m. L of blood. How many m. L of blood did he obtain from all of his patients? 5

UNIT 5 - PEMDAS Example – An MT is counting leukocytes (white blood cells). She counts four areas, adds the four areas together, and then multiplies by 50 to obtain the correct count. If the counts are 32, 29, 28 & 33, what is the total leukocyte count? 6

FRACTIONS IN HEALTHCARE The metric system is the most commonly used system of measurement in healthcare today. Because it is based on power of tens, the metric system uses the decimals to describe values less than 1. The household system and the apothecary system are also used. Both of these systems require the use of fractions to describe values less than 1. 7

REDUCING FRACTIONS Example– A patient is admitted into the respiratory unit with congestive heart failure. Upon admission, he weighed 285 lb. As a result of taking Lasix® to reduce his fluid retention, he had lost 45 lb by day 10 of his hospital stay. Express the amount of weight he lost as a fraction of his original body weight (in lowest terms). Express his weight at day 10 as a fraction of his original body weight (in lowest terms). 8

UNIT 6 – ADDING FRACTIONS To add fractions or mixed numbers: 1. Find the least common denominator (LCD). 2. 3. 4. Build up each fraction to contain the LCD. Add numerators and keep the denominator. For mixed numbers, add the whole numbers together as well. Reduce to lowest terms if possible. Example: Add LCD = 24 9

UNIT 6 – ADDING FRACTIONS 10

UNIT 7 – SUBTRACTING FRACTIONS 11

UNIT 7 – SUBTRACTING FRACTIONS Example – An RT studies the following chart on time required to take a chest X-ray, based on the size of the patient’s chest. How much more time is required for a patient with a 31 cm chest than a person with a 20. 5 cm chest measurement? 12

UNIT 8 - MULTIPLYING FRACTIONS To Multiply Fractions: 1. Convert any mixed numbers to improper fractions first. 2. 3. 4. Simplify before you multiply by cancelling any common factors first. Multiply numerators & multiply denominators. Reduce to lowest terms if possible. Example: 2 1 13

UNIT 8 - MULTIPLYING FRACTIONS 14

UNIT 8 - MULTIPLYING FRACTIONS Example – A home health care assistant prepares 10 ½ ounces (oz) of infant formula. The mixture is 1/3 formula and 2/3 water. How much formula does she need to make the 10 ½ oz total? How much water does she need to make the 10 ½ oz total? 15

UNIT 9 – DIVIDING FRACTIONS Dividing fractions is similar to multiplying fractions, except… You must rewrite the division problem as multiplying by the reciprocal first, then solve. Example – A pharmacist has a 9 gram (g) vial of medication. How many 2/3 -g doses can be obtained from this vial? 16

UNIT 9 – DIVIDING FRACTIONS Example – A cardiac nurse notes that an intravenous (IV) bag is 2/5 empty. If the patient has absorbed 600 milliliters (m. L) of the IV solution, how much solution was in the bag when it was full? 17

COMPLEX FRACTIONS Complex fractions are, well…. complex! In order to solve properly, keep in mind that there is a separate order of operations in the numerator & denominator. Example – Reduce the complex fraction: 18

MIXED OPERATIONS INVOLVING FRACTIONS 19